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Author Topic: Converting to DNG - do you lose quality?  (Read 28732 times)
madmanchan
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« Reply #60 on: July 31, 2008, 09:31:22 AM »
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So make like with the examples.

Also, does the existence of these profiles mean that Magne Neilsen is going to get more of my money?
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DarkPenguin, the new Camera Matching profiles demonstrate that the updated DNG 1.2 profiles can be used to match the "vendor looks" (i.e., the color rendition provided by the camera manufacturers themselves). The DNG Profile Editor can be used to tweak these further, or do another 'matching' profiles, such as if you prefer to make the default color rendition similar to, say, SilkyPix, Capture One, Bibble, etc. We've internally produced a few Camera Matching profiles as examples of what can be done. We're hoping the community will take it up from there. You can even do funky things like make an Olympus look like a Canon, or vice versa.

As to whether Magne will get more of your money, well ... one possibility is that a market will develop around custom profiles built with the DNG Profile Editor or another tool. Any custom-built software (Magne writes his own software, and has a lot of experience doing this) can build DNG 1.2 profiles; the FAQ even has sample code to help developers get started doing this. We certainly encourage having a market build up around it. But whether Magne gets involved personally ... I have no idea.
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madmanchan
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« Reply #61 on: July 31, 2008, 09:41:56 AM »
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That's all nice and dandy but, taking Panokeeper's and Chan's parallel discussion into consideration, what would have happened if Nikon for example had decided to take up DNG and abandon their proprietary files 2-3 years ago? Would we all have to suffer the intolerable colours ACR sometimes comes up with (used to??) from Nikon files regardless the raw converter we would use? Would Nikon D3/D300/D700 be able to take advantage (if they opted to) as they can do now of excellent automatic correction of colour aberrations in their raw files?

NikosR, IMO, no this would not have happened. The color rendition depends on the color profile stored with the DNG. Camera manufacturers that write DNG files are free to use their own color profiles, not the ones provided by Adobe. Color profiles are just tags stored in the DNG metadata. So if someone else can come up with better profiles and stick them into the DNG, more power to 'em.

Furthermore, DNG has a MakerNote tag that can store whatever proprietary information a camera manufacturer (Canon, Nikon, etc.) wants, whether this be lens correction data, vignette compensation data, etc.

In fact, the DNG Converter, when building a DNG file, already copies over all the proprietary tag data and stuffs it in the MakerNote, even though CR/LR doesn't understand how to interpret the data. The important thing is that the metadata is preserved (as opposed to being tossed out).

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I don't know the answer to these questions but all I can say is that I can see no standard being really viable unless it is developed and agreed upon by all major parties involved AND manages to both protect intellectual property and confidentiality AND does not indirectly hinder innovation (or what each party views as their strategic or competitive advantage).
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Hopefully my answers above help demonstrate that the DNG spec does allow manufacturers to protect IP and innovation (the actual spec even discusses this exact point, and the reason for this MakerNote tag). Regarding the major parties ... well, we do have discussions with all the big players, though some are more happy/willing to discuss DNG than others. The idea behind handing it over to ISO would certainly imply multiple parties being involved.
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NikosR
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« Reply #62 on: July 31, 2008, 09:47:45 AM »
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NikosR, IMO, no this would not have happened. The color rendition depends on the color profile stored with the DNG. Camera manufacturers that write DNG files are free to use their own color profiles, not the ones provided by Adobe. Color profiles are just tags stored in the DNG metadata. So if someone else can come up with better profiles and stick them into the DNG, more power to 'em.


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But, correct me if I'm wrong since I'm far from an expert, if part of the problem is (was?) matrix vs look-up table RGB conversions and DNG could not support look-up table conversions wouldn't that have disallowed users to get the most colorwise from their raw files?
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Nikos
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« Reply #63 on: July 31, 2008, 10:14:29 AM »
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DNG just holds data.  It doesn't handle the conversions.

If your favorite converter starts to support DNG it wouldn't have to use the Adobe profiles.  It could still do whatever it does now.
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NikosR
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« Reply #64 on: July 31, 2008, 11:38:47 AM »
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DNG just holds data.  It doesn't handle the conversions.

If your favorite converter starts to support DNG it wouldn't have to use the Adobe profiles.  It could still do whatever it does now.
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I will infer from the answers given above from Pano and Chan that the DNG specification prescribes the type of profiles for conversion and the DNG files contain them. Which means the profiles used would be of the type Adobe have prescribed (i.e. matrix rather than look-up table conversion up to very recently). Do you know otherwise?
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Nikos
Panopeeper
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« Reply #65 on: July 31, 2008, 11:57:18 AM »
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I will infer from the answers given above from Pano and Chan that the DNG specification prescribes the type of profiles for conversion and the DNG files contain them. Which means the profiles used would be of the type Adobe have prescribed (i.e. matrix rather than look-up table conversion up to very recently). Do you know otherwise?
The point of the standardization is, that any raw processor can convert any raw file without having to know the specifics of the actual camera. Some raw processors were (are?) using the maker's proprietory information from the DNG file. While this remains possible, it defeats the purpose of the standardization.
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Gabor
NikosR
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« Reply #66 on: July 31, 2008, 12:05:16 PM »
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The point of the standardization is, that any raw processor can convert any raw file without having to know the specifics of the actual camera. Some raw processors were (are?) using the maker's proprietory information from the DNG file. While this remains possible, it defeats the purpose of the standardization.
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So if Nikon for example had standardized on the DNG specification (I insist on specification and not just file format) that would mean in my example they would have to use matrix-based profiles. Which many people including you have argued, and Adobe have implicitly half admitted with their latest DNG specification, are not totally capable of correctly converting the raw data to RGB color information for all different illuminants mainly due, as I understand it, to non-linear sensor response.

Taking Jeff's statement above about Adobe teaching the manufacturers about how to properly write a raw file, one might argue that the manufacturers have 'taught' Adobe something about raw to RGB color mapping
« Last Edit: July 31, 2008, 12:05:59 PM by NikosR » Logged

Nikos
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« Reply #67 on: July 31, 2008, 01:17:19 PM »
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I will infer from the answers given above from Pano and Chan that the DNG specification prescribes the type of profiles for conversion and the DNG files contain them. Which means the profiles used would be of the type Adobe have prescribed (i.e. matrix rather than look-up table conversion up to very recently). Do you know otherwise?
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It's just a profile.  It doesn't change the data.  If that doesn't match the software's needs then the software can continue to do whatever it used to do.  It just has to look for its data in slightly different spots.

This does defeat some of the promise of DNG.  Your software would still need to know about your specific camera model and pick an appropriate profile.  If the software used the built in profiles it could just decode the file and would have no need of knowing anything about the D80 (or whatever) that was used to take the photo.

So, yeah, if the software wants to use the profiles it pretty much does specify the conversion.  But if it doesn't you get the same thing you do now.
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Panopeeper
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« Reply #68 on: July 31, 2008, 01:26:32 PM »
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I insist on specification and not just file format
Actually, the file format of DNG is the same as that of most raw files, namely TIFF.

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that would mean in my example they would have to use matrix-based profiles
They would have to attach the matrixes for the primary conversion, and now they could attach the profiles as well to "fine tune" the result of the primary conversion.

Furthermore, they could include all proprietory information as well, but those would remain proprietory.

Note, that the proprietory information is necessary for example to figure out in-camera settings, like contrast, picture style, and some other features. However, the color reproduction is based usually on the specific knowledge of the sensor (spectral characteristics), i.e. it is hard-wired in the programs.

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Which many people including you have argued, and Adobe have implicitly half admitted with their latest DNG specification, are not totally capable of correctly converting the raw data to RGB color information for all different illuminants

1. The new features (i.e. profiling) are a huge enhancement. I re-did a few conversions and am surprized by the huge difference (positive), using the new profiles, created by Adobe. I am very pleased by this.

2. Notwithstanding my pleasure with the new profiles, the basic problem remains: that the matrix conversion limits what a program can do. I do not know if and how much this limitation is regarding specific cameras. I would expect that Adobe investigated this question, but I guess we won't see the result.

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mainly due, as I understand it, to non-linear sensor response
Caution with this. There are two totally different meanings of "non-linearity" in conjunction with sensors. The issue at hand is the spectral response, and this aspect can be ignored here, for nothing will change that in the near future.
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Gabor
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« Reply #69 on: July 31, 2008, 10:16:21 PM »
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Taking Jeff's statement above about Adobe teaching the manufacturers about how to properly write a raw file, one might argue that the manufacturers have 'taught' Adobe something about raw to RGB color mapping
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Not at all...if what you want is Nikon or Canon "Looks" (which btw are neither technically accurate nor always "pleasing"), DNG has now given users the ability to do so...but in fact, the more accurate Adobe profiles and the ability to edit those profiles is a pretty big technical advance (which none of the camera companies have ever come up with–and don't even think of saying Phase One...they just co-opted ICC Input profiles).

In point of fact, the camera companies are the newest kids on the block when it comes to color. Up till 2000 or so, they NEVER had to worry about COLOR...all they had to worry about was forming a light tight seal for the film and the formation of the image through the lens. To think that Nikon or Canon somehow have some long standing understanding and tradition when it comes to color is, well, pretty far off the mark. They've been making this stuff up as they go...all they REALLY know is lenses and film transport.
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ErikKaffehr
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« Reply #70 on: July 31, 2008, 11:45:28 PM »
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These reminds me of an interview with a manager at Konica Minolta after the Konica and Minolta merger. Konica has been a film company, so the Minolta folks were in for a culture shock regarding color. Minolta was thriving for correct color while Konica was thriving for pleasant color.

Erik


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Not at all...if what you want is Nikon or Canon "Looks" (which btw are neither technically accurate nor always "pleasing"), DNG has now given users the ability to do so...but in fact, the more accurate Adobe profiles and the ability to edit those profiles is a pretty big technical advance (which none of the camera companies have ever come up with–and don't even think of saying Phase One...they just co-opted ICC Input profiles).

In point of fact, the camera companies are the newest kids on the block when it comes to color. Up till 2000 or so, they NEVER had to worry about COLOR...all they had to worry about was forming a light tight seal for the film and the formation of the image through the lens. To think that Nikon or Canon somehow have some long standing understanding and tradition when it comes to color is, well, pretty far off the mark. They've been making this stuff up as they go...all they REALLY know is lenses and film transport.
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DarkPenguin
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« Reply #71 on: August 01, 2008, 12:02:07 AM »
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These reminds me of an interview with a manager at Konica Minolta after the Konica and Minolta merger. Konica has been a film company, so the Minolta folks were in for a culture shock regarding color. Minolta was thriving for correct color while Konica was thriving for pleasant color.

Erik
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I miss Konica Impressa 50.
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NikosR
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« Reply #72 on: August 01, 2008, 01:19:39 AM »
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Not at all...if what you want is Nikon or Canon "Looks" (which btw are neither technically accurate nor always "pleasing"), DNG has now given users the ability to do so...but in fact, the more accurate Adobe profiles and the ability to edit those profiles is a pretty big technical advance (which none of the camera companies have ever come up with–and don't even think of saying Phase One...they just co-opted ICC Input profiles).

In point of fact, the camera companies are the newest kids on the block when it comes to color. Up till 2000 or so, they NEVER had to worry about COLOR...all they had to worry about was forming a light tight seal for the film and the formation of the image through the lens. To think that Nikon or Canon somehow have some long standing understanding and tradition when it comes to color is, well, pretty far off the mark. They've been making this stuff up as they go...all they REALLY know is lenses and film transport.
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Ha Ha! You do have a way of diverting the discussion to where it suits you. Still, I'm pretty sure they started to deal with the intricacies of dealing with data from a real life sensor much before Adobe did  and my personal opinion is that Nikon color coming out of Adobe's converters up to now has been neither accurate nor pleasing.

If all we had all this time was Adobe's color, red would be something only film guys would remember about. And yes, I too like Adobe's recent effort with the new DNG and profiles. All my initial tests up to now show a positive step towards the right direction. But the point remains. Adobe seem to be now where Nikon, for example, have been, colorwise, for the last 4 years or so. I have the suspicion that if  all there was all this time was Adobe's interpretation of camera color and if we didn't have all the user complaints too, Adobe would not have progressed to what was announced a few days ago.  Don't get sidetracked. Many user comlplaints were in fact due to Adobe not producing the camera preset colour but many high-end users also were complaining about Adobe not producing 'correct' colour.

The new type of profiles and the editor are a big step in the right direction. Adobe themselves admit that it was not only done to emulate camera jpegs as you like to put it. If that were the case we wouldn't have the new Standard profiles, we would only have the emulation ones. That's competition. It is a good thing for us consumers. I believe if camera manufacturers had adhered to the first DNG spec some years ago this progress would not have occured.

Look one think I can deduce from all discusssions in this thread is that in an ideal world a common format would be a good thing for us photographers. I just don't think that the issue is as important as you make it to be.

I feel (just my personal opinion) that the problem to be solved by a common standard is more important for the business plans of giant sw manufacturers like Adobe than for photographers and I still remain unconvinced if the way DNG was specified and 'marketed' made it a good candidate for this given all the technical and business realities.

There are two ways to create standards like this. There should either be a win-win deal for all parties involved OR the strongest prevails. Maybe the time is now approaching. We'll see.
« Last Edit: August 05, 2008, 05:00:49 AM by NikosR » Logged

Nikos
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